automatic MITSUBISHI GALANT 1989 Service Owner's Guide

13-346AUTO-CRUISE CONTROL SYSTEM - Troubleshooting6-2.
CHECKING THE PARK/NEUTRAL POSITION SWITCH CIRCUIT
ECU
-I
J
(12)
2mi
Park/neutral
position
switch
zc:
1
&
A
I
3pry
iz,:
T
3qpIII
1 ? 3;m456
/I
Starter motor
to the control unit, park/neutral position switch,
starter motor, and to ground; the cancel signal is
therefore input to the control unit, thus canceling
the constant-speed travel.
Description of operation
The park/neutral position switch also functions as
the switch for the starter.
If the selector handle is moved to the “N” posi-
tion during constant-speed travel, current flows
Troubleshooting hint
Diagnostic-No.16 (automatically cancelled)
ECU terminal voltage
Terra’Signal
2Park/neutral position switch At all times
ConditionsTerminal voltage
12v
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-347
6-3. CHECKING THE CLUTCH PEDAL POSITION SWITCH CIRCUIT
Ignition
switch
Junction block
ECU
NOTENO: OFF at all time
Description of operation If the clutch pedal is depressed during constant-
speed travel, the contacts of the clutch pedal position switch close, with the result that the
cancel signal is sent to the control unit, so that
the current to the electromagnetic clutch of
Troubleshooting hint
Diagnostic-No.16 (automatically cancelled)
ECU temrinal voltage the actuator is discontinued within the control
unit, thereby canceling the constant-speed travel.
The flow of current is to the ignition switch (IGI),
fuse No. (9) of the junction block, the
clutch pedal position switch, and the control unit.
/ Te;z,nal 1Conditions Terminal voltage
Clutch pedal position
switch When the clutch pedal is depressed
When the clutch pedal is not depressed12v
ov
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13-348AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
7. CHECKING THE CIRCUITS RELATED TO THE ACCELERATOR SWITCH
OFF FUNCTION
(16)
[ml
Ignition
switch
Junction
block
r------_--- ___--- ---
4
A/T
control
module
NOTENC: ON at all time Iescription
of operation
The accelerator switch is a switch that
detect-s the
operational status of the accelerator pedal; it is one of the sensors of the automatic transaxle.
Because the status of the accelerator pedal during constant-speed driving is non-operational, the ground circuit (transistor Tr2) of the accelerator
switch is switched OFF only during constant-speed
driving in order not to interfere with the function of
the automatic transaxle.
Troubleshooting hint ECU terminal voltage
Terminal
1
No. , SignalConditions
Terminal voltage
6’ Control unit power sup-
At all times12vply (IG2)
16
Accelerator switch When the accelerator pedal is depressed
o
v
When the accelerator pedal is not depressed
12v
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13-352AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
Trouble symptomProbable causeCheck chart No.
Remedy
l The set vehicle speed varies Malfunction of the ve-No.4Repair the vehicle speegreatly upward or downward.hicle speed sensor cir-l “Hunching” (repeated alternatingsensor system, or re-witplace the part.
acceleration and deceleration) oc- curs after setting is made.
Malfunction of the spee-
dometer cable or spee-
dometer drive gear
Auto-cruise vacuum
No.5Repair the auto-cruisepump circuit poor con-vacuum pump or replactactthe part.
Malfunction of the auto-cruise vacuum pump Malfunction of the ECU
-Replace the ECU.
The auto-cruise control system is not Damaged or discon-If the input check code Repair the harness or rezanceled when the brake pedals is netted wiring of the stopNo.23 indicates a mal-
depressed.light switch input circuit; function. No.6place the stop light
switch.
brake switch (for auto-cruise control) malfunc-
tion (short-circuit)
Auto-cruise vacuum
No.5Repair the harness or repump drive circuit short- place the auto-cruise va
circuit.cuum pump.
Malfunction of the ECU
-Replace the ECU.
The auto-cruise control system is not Damaged or discon-If the input check code
Repair the harness, or:anceled when the clutch pedal is netted wiring of clutchNo.26 indicates a mal-repair or replace thedepressed. (vehicles with a manual
pedal position switchfunction. No.8clutch pedal position
ransaxle)input circuitswitch.
It is canceled, however, when theIrake pedal is depressed.) Clutch pedal position
switch improper installa-
tion (won’t switch ON)
Malfunction of the ECU
-Replace the ECU.
*he auto-cruise control system is not Damaged or discon-If the input check code
Repair the harness, or:anceled when the shift lever is netted
wiring of park/No.26 indicates a mal-repair or replace the
noved to the “N” position. (vehicles neutral position switchfunction. No.7park/neutral position
vith an automatic transaxle)input circuit switch.t is canceled, however, when thebrake pedal is depressed.)
Improper adjustment of
park/neutral position
switch
Malfunction of the ECU-Replace the ECU.
anc$ decelerate by using the SET Temporary damaged orNo.2Repair the harness or re-disconnected wiring of
SET switch input circuitplace the SET switch.
Auto-cruise vacuumNo.5Repair the harness or re-pump circuit poor con-
tactplace the auto-cruise va-
cuum pump and actua-
tor.Malfunction of the auto-cruise vacuum pump
and actuator (including
clogging of negative
pressure passage)
Malfunction of the ECU-Replace the ECU.
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-353
Trouble symptom
Probable causeCheck chart No.Remedy
Cannot accelerate or resume speed
No.3
by using the RESUME switch. Damaged or discon- netted wiring, or short-
Repair the harness orcircuit, of RESUMEreplace the RESUMEswitch.
switch input circuit
Auto-cruise vacuum
No. 5Repair the harness orpump circuit poor con-replace the auto-cruisetactvacuum pump and
actuator.
Malfunction of the auto-cruise vacuum pump
and actuator (including
air leak from negative
pressure passage)
Malfunction of the ECU-Replace the ECU,
4uto-cruise control system can be Malfunction of theNo.4Repair the vehicle-set while traveling at a vehicle speed vehicle-speed sensorspeed sensor system,3f less than 40 km/h (25 mph), orcircuit‘or replace the part.
there is no automatic cancellation at
that speed.
Malfunction of thespeedometer cable orthe speedometer drivegear
The indicator light of combination
neter does not illuminate. But auto-cruise control system is
iormal.)
Malfunction of the ECU-Replace the ECU.
Damaged or discon--Repair the harness ornetted bulb of indicatorreplace the bulb.light
Harness damaged ordisconnected
vlalfunction of control function by Malfunction of circuit re-No. 9Repair the harness orIN/OFF switchrng of ELC 4 ATlated to accelerator
replace the part.accelerator switchswitch OFF function
Non-operation of torque converter
:lutch, 2nd gear hold, etc.) Malfunction of the ECU
Overdrive is not canceled during Malfunction of circuit re-No. 10Repair the harness or
ixed speed driving. lated to overdrive can-replace the part.cellation, or malfunction\lo shift to overdrive during manualIriving.
of ECU
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13-354AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
CHECK CHART 1. CHECKING THE CONTROL UNIT POWER SUPPLY CIRCUIT
IgnitionswitchI
Cruise-control
switchI(8)
pmTzREq
4 atAuto-cruise control unit
13A0377
Description of operation
When the cruise control switch (CRUISE) is switched ON whilethe ignition switch is ON, current flows to the ignition swrtch(IG,), to fuse No.(ll) of the junction block, and to the
cruise-control switch (MAIN switch), the control unit, and to
ground.When the ignition switch is turned OFF, the MAIN switch in thecruise control switch is also turned OFF.
Troubleshooting hint ECU terminal voltage
Terminal SignalConditions TerminalNo.voltage
2Control unitWhen the cruise-Battery
power supply control switch positive
(CRUISE) isvoltage
switched ON.
6. 8Control unitgroundAt all timesov
NOTEl :The connector Nos. in Section “AUTO-CRUISE CONTROL RELATED HARNESSES” and the connector names in the
junction block are represented.
(Applicable on the next page and subsequence.)
2. CHECKING THE SET SWITCH
I
Auto-cruise ’control unitT
v“17 3
A-3SETCrulse-OFFcontrolTONswitch
>: 13
63)
13AO386Description of operation
When the SET switch is switched ON (at the vehicle speed desired to be maintained, and with the CRUISE switch of the
cruise-control switches ON) that vehicle speed is maintained as
a constant speed.
Furthermore, the constant speed is gradually reduced (the “coasting” feature) when the SET switch is pressed and held
while the vehicle is traveling at the previously set constant
speed, and, when the SET switch is released, the vehicle thenmaintains that newly set constant speed (the speed at which
the SET switch was released).
Current flows to the control
unit. the cruise control switch
(“SET”), and to ground.
Troubleshooting hint
Diagnostic-No.15 (automatically cancelled)
ECU terminal voltage
Terminal SignalConditions TerminalNo.voltage
17SET switch
When the SETovswitch is switchedON.
When the SET
;yv$h is swrtched Battery
positive
voltage
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-355
3. CHECKING THE RESUME SWITCH CIRCUIT
Auto-cruisecontrol unit
--f
Y
Cruise-control
switch
Description of operation
The set speed (before cancellation) resumes when the RE- SUME switch is
swrtched ON, even if the constant-speed
control has been cancelled.That speed will not resume, however, even if the RESUMEswitch is switched ON, if the CRUISE switch is switched OFFand if the vehicle speed decreases to 40 km/h (25 mph) orlower.
In addition, when the RESUME is switched ON and held whi!ethe vehicle is traveling at a constant speed, the vehicle speedwill increase; the speed at which the switch is subsequently released will become the newly set constant speed.
Current flows to the control unit, the cruise control switch
(RESUME), and to ground.
Troubleshooting hint
Diagnostic-No.1 5 (automatically cancelled)
ECU terminal voltage 13AO382
Terminal
Signal ConditionsTermrnalNo.voltage
18RESUME
When the RESUMEOVswrtchswitch is switchedON.
When the RESUME
Batteryswitch is switchedpositiveOFF.voltaae
4. CHECKING THE VEHICLE-SPEED SENSOR CIRCUIT
Auto-cruisecontrol unit
Combinationmeter
Junction
block
(6)
Description of operation
The vehicle-speed sensor is installed within the speedometer; itsends to the controlunit pulse signals that are proportional tothe rotatron speed (i.e., the vehicle speed) of the transaxle’soutput gear.
This vehicle-speed sensor IS the reed switch type of sensor; itgenerates four pulse signals for each rotation of the speedo-
meter’s driven gear.
Troubleshooting hint
Diagnostic-No.12 (automatically cancelled)
ECU terminal voltage
TerminalSignal Conditions
TerminalNo.voltage
19Vehicle-speedMove the vehicleov-0.7vsensorforward slowly.tFlashingJ3V-higher
13A0381
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13-356AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
5. CHECKING THE AUTO-CRUISE CONTROL VACUUM PUMP Description of operation
Hold modeWhen the SET switch is turned ON by the driver turning theCRUISE switch ON when a determined speed is reached, thecontrol unit receives a set signal, and turns the auto-cruisevacuum pump motor ON. After the constant speed is reached,
the motor, control valve and release valve are repeatedly turned
ON and OFF according to driving conditions.
Ignitionswitch
Auto-cruise
Acceleration mode
When the RESUME switch is pressed, the control unit receives
a RESUME signal and it not only turns the auto-cruise vacuum
pump motor ON but also turns the control valve and release
(10)
control ’ “”unit13AO376
valve ON (valve is closed)
Deceleration mode
When the SET switch is held down, the control unit receives a
set srgnal and it not only turns the auto-cruise vacuum pumpmotor and control valve OFF (valve is opened) but also turns therelease valve ON (valve IS closed).
Release modeWhen the CRUISE switch is turned OFF, the control unit
receives a cancel signal and it not only turns the auto-cruise
vacuum pump motor OFF but also turns the control valve andrelease valve OFF (valve is opened).
Troubleshooting hint
Diagnostic-No.1 1 (automatically cancelled)
ECU terminal voltage
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13-358AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
8. CHECKING THE CLUTCH PEDAL POSITION SWITCH CIRCUIT
13A0378
Description of operation If the clutch pedal is pressed when driving at a constant
speed, the clutch pedal position switch is turned ON and a
cancel signal is input to the control unit and the determined driving speed is canceled because current flows to the
clutch pedal position switch junction block from the control
unit and to ground.
Troubleshooting hint
ECU terminal
voltage
Terminal Signal Conditions
TerminalNo.voltage
1Clutch medalWhen the clutchov
Iposition switchpedal is depressed.IWhen the clutch
pedal is not
depressed.Battery
positive
voltage
9. CHECKING THE CIRCUITS RELATED TO THE ACCELERATOR SWITCH OFF FUNCTION
>
Ignition switch
The accelerator switch is a switch that detects the operationalstatus of the accelerator pedal; it is one of the sensors of theautomatic transaxle.Because the status of the accelerator pedal during constant-speed driving is non-operational, the ground circuit (transistorTr2) of the accelerator switch is switched OFF only duringconstant-speed driving in order not to interfere with the functionof the automatic transaxle.
Troubleshooting hint ECU terminal voltage
TerminalNo.Signal ConditionsTerminalvoltageII3Control unit
At all times Battery
power supply positive
voltage
I gAccelerator
switch
NOTENC: Indicates ON at all time
1 Not rn operation / OFF ) ON 1
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-361
Wi
thscan tool
With voltmeter
Auto-cruise control
\
Data link
connector
III
n
,
/r-I
/Ground161009
Data link
connector
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On-board diagnostic checking is performed when there has
been an automatic cancellation, without cancel switch opera-
tion.
(1) The following two methods can be used for checking the diagnostic. Note that the data link connector is locatedunder the driver’s side instrument panel.
@ If a scan tool is used
Connect the scan tool’s socket and connector to the
cigarette lighter socket and the data link connector, and
set the tester. Use the tester according to its operation
instructions; display the diagnostic trouble code num-
ber and then check.
@ If a voltmeter is used Connect a voltmeter between the ground terminal and
the terminal for auto-cruise control of the data link con-
nector.
It is possible to discover which circuit is the cause of
the cancellation by verifying the indication shown by
the voltmeter with the display patterns shown on the
next page.
(2) When the diagnostic trouble code No. is displayed, check by referring to the check chart applicable to that number.
NOTE
Canceling the diagnostic trouble codes
The diagnostic trouble codes remain in memory until the battery is turned off but they can be canceled in the follo-
wing ways without disconnecting the battery terminals.
@ By turning on the ignition switch.
@ By turning the main switch ON while the SET switch is ON and then, within 1 second, turning the RESUME
switch ON. (Put into condition for input check recep-
tion).
@ By turning ON the SET switch and stop light switch at the same time and continuing the ON condition for 5
seconds or more.
@I By checking that the diagnostic trouble codes are canceled using a scan tool or voltmeter.